Piezoresistive (PZR) stress sensors can be used for position sensing for microelectromechanical system (MEMS) scanning mirrors in applications such as scanned beam display systems. The amount of mechanical strain detected by the sensor is related to the position of the scanning mirror. Thus, a strain signal obtained by the sensor may be used as a feedback input in the scanning control system to provide correction to the drive signal to facilitate control of the movement of the scanning mirror. Ideally, the strain sensor is capable of producing a signal in response only to a certain kind of motion of the scanning mirror, for example torsional deformation of the flexures supporting the scanning mirror. In practice however, such sensors may be sensitive to other types of motion which result from deviation from the ideal case caused by material fabrication or process variation. For example variations in certain properties of the sensor can cause it to generate a feedback signal having a component due to bending deformation of the flexures in addition to the torsional response. Consequently, the detection of undesired deformations by the sensor may cause the scanning control system to apply a less than ideal and/or an incorrect control signal since the feedback signal from the sensor may contain components due to motion other than the type of motion being controlled.
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